Said dahl



(No Modei.)

J. E. LOW 3v M. DAHL.

TOOL HDLDBR. v

Patented Feb. 7, 1893.

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JU@ T linterna dTaTns FaTnNT @Trione JAMES E. IiOldT AND MAGNUS DAI-IL,OF OIIICAGO, ILLINOIS; SAID DAHL ASSIGNOR TO SAID LOV.

SEGIFICATXON forming part of Letters Patent No. 491,316, dated February7, 1893. Application iiled September 22. 1890. Serial No. 365.794. (Nomodell) To onli whom it may concern:

Be it known that we, JAMES E. LOW and MAG-NUS DnHL, of Chicago, in thecounty of Cool; and State ot Illinois, have invented oertain new anduseful Improvements in Toollrlolders or Clutches; and we do herebydeclare that the following is a full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, and to theletters of reference marked thereon, which form a part of thisspecification.

This invention has for its object to provide certain improvements in theconstruction of rotating tool holders such, for example, as are commonlyused in connection with dental engines, though adapted for other uses.

A principal feature ci the improvement consists in the employment of atoggle as a inea-ns for giving a longitudinal movement to one of theparts ofthe clutch with respect to an other for the purpose of closingthe clutch upon the shank ot the tool.

The invention consists, however, in other features ot construction alsoas will hereinafter fully appear from the description of theaccompanying drawings.

In said drawings: Figure l is a longitudinal section of the completetool holder taken in the plane in which the toggle works, the members ofsaid toggle and its immediate connections being shown in side elevation.The toggle in this ligure is shown retracted, giving the grippingmembers ot the clutch their open position ready to receive the shank ofthe tool. Fig. 2 is a similar view of theparts immediately concernedwith the toggle mechanism, showing the toggle extended and the clutchgripping the shank of a tool. Eig. 3 is a longitudinal section of theexternal and non-rotating parts of the tool holder as employed inconnection with dental engines and an elevation of the interior androtating parts, the section being taken in a plane at right angles tothat ot the section shown in Figs. l and 2, or, in other words, at rightangles to the plane in which the toggle works. Fig. d is a transversesection in the plane oli' the line e--e of Fig. l.

In the adaptationot' the invention to use in connection with dentalengines illustrated in the foregoing iigures, the external andnonrotating parts which inclose the rotating inembers consist of a tipA, a cylindric sleeve A secured to the tip A, a cylinder A2 separated bya distance 'from the cylinder A', a tubeguard or sleeve A3 screwed tothe cylinder A2, and a longitudinally sliding external sleeve A4covering the space between the cylinders A and A2 and carrying thepresser by which the interior toggle is extended. Vithin the shellcomposed of these members is a continuous, rotating tube B extendingfrom the iuterior shoulder a at the outer end of the tip A to the outerend of the cylinder A2. Within said cylinder the tube bears against anannular shoulder a and thereby retains said cylinder outwardly inposition.

B is a plug screwed into the inner end of the tube B and provided withan annular shoulder h which extends beyond the adjacent periphery ofsaid tube and into bearing against the end of the shell cylinder A2.This plug thus retains the cylinder A2 inwardlyin place. At h the tube Bis provided with a circumferential groove into which is iitted a ringd2, formed in seinieircular halves which are fastened to the shellcylinder A by screws o3 or otherwise, and this ring holds the parts A'and A in their proper relation to said tube For a short distance fromthe end of the tube B which occupies the tip A of the shell its interioris tapered or contracted, as clearly indicated in Figs. l and The tube Bis provided with a longitudinal slot h2 between the proximate ends ofthe cylinders A and A2 of the shell, and through this slot projectsinwardly the presser A5, movable in the slot by a lengthwise nuovementof the sleeve or shell A4 for the purpose of pressing inward andextending the toggle. Thus entering the slot b2, the presser must rotatewith the tube B. To have, at the saine time, proper engagement with thesleeve A4 so as to be slid thereby, it is attached to a ring CL4 whichis revoluble Within the slide and is held in place with respect theretoby the rings of a5 secured to and within the said slide. The mode offastening the rings a5 to the sliding cylinder AA1 here shown isspecially illustrated in section in Fig. fl wherein c di are pins thrustthrough both the slide and the rings. The ring a4 is shown fastened toTOO the presser A5 by a screw a7, accessible through a hole a8 in theslide.

C is a rod fitted to slide lengthwise in the tube B and extending fromthe slot b2 to or nearly to the mouth of the tip A. At its end adjacentto said mouth it is provided with, or constructed to form, a springclutch which may close upon the shank of a tool T by outward movementwithin the tapered end portion of the tube B and may open or spread itsjaws to release the tool upon the retraction of the rod. Such a springclutch construction involves the familiar device of lengthwise slits ina tube, the jaws separated by the slits being forced toward each otherto grip a tool shank as they are pushed into the contraction of a tubesurrounding it and springing apart again to release the tool upon theirretraction from such contracted portion of the tube. In the presentinstance the rod C :is not itself split at its end but is provided witha longitudinally drilled hole c which receives a second, split orslitted tube C fastened securely in the hole c and presenting a seriesof compressible jaws c c beyond the end of the rod C and within thetapered portion of the tube B. 3y making the jaws c of a tube separatefrom the rod C they may be hardened more conveniently and reliably andmay be removed and replaced as occasion may require. No novelty isclaimed for this feature.

At its opposite or inner end the rod C is attached to a toggle composedof the arms C2 C3 jointed to each other and one of them, C2, jointed tothe extremity of the rod C. The other arm C3 is, at its outer end,jointed to a stationary part C4, here shown in the form of a disksecured by a screw c2 to a plug C5 which is screw-threaded into the openend of the tube B. This construction gi'ves adjustability of position tothe stationary part C4, and by such adj ustability of said part the rodC may be slid forward in the tube B to a greater or less extent, asdesired, ora delinite throw may be given thereto by a certaindeterminable movement of the toggle presser. The toggle C2 C3 isarranged with its arm C2 opposite the slot Z22 of the tube B and has itsmovement in the plane of said slot, and when the toggle is bent orretracted, as by a spring c3, said toggle will be deilected toward orinto said slot b2, as shown in Fig. 1. The presser A5 is arranged tobear on the outersurface of said toggle arm C2so that by movingtheslideAl which carries said presser in a direction away from the tipof the instrument said presser will slide upon said outer surface of thearm C2 and straighten the toggle, thereby causing the rod C to moveoutwardly within the tube B and the clutch to clamp the tool shank, asshown in Fig. 2. The movement of the slide and its presser is desirablysuch that the presser will be carried at its point of bearing on thetoggle a little past the central joint of the latter, as indicated inFig. 2, so that the tendency of the toggle to flex will contribute tothe retention of vthe presser in its proper place when the toggle isextended. XVe prefer to give to the surface of the toggle arm upon whichthe presser bears the longitudinally and inwardly curved or concavecontour illustrated in Figs. 1 and 2, so that the movement of the clutchrod C will be accomplished in a relatively short movement of the slideA4 and its presser A5. Ve also prefer to provide the presser A5 with ananti-friction roller a9 to render the movement of the slide more easyand to prevent wear. Manifestly an inward projection like A5 upon thesliding ring to which it is attached is only needful to the avoidance oftoo great protrusion. of the toggle, when retracted, through the slot ofthe tube B, and when the toggle is allowed to protrude sufficiently saidprojection may be omitted and the ring itself will become the presser.

rlhe rotation of the tube B is accomplished by the application of forceto the plug B for which purpose said plug is shown provided with a shankb3 to which the power is applied through any suitable means. In the caseof a dental engine suoli means will commonly be a rotating, iiexibleshaft or other well known device for the purpose, but in otheradaptations of the invention, as for example, to a watchmakers lathe,the shank b3 may be provided with a pulley to receive a driven belt orcord. The tube rotates the plug C'd which, through the screw c2, rotatesthe stationary member C1 of the toggle clutch mechanism and the partsconnected therewith. If desired, the rod C,instead of being rotatedthrough the toggle, may be splined or in any other familiar way made torevolve with the tube B While allowing longitudinal movement thereof.

In adapting the invention to other uses than that of a dental enginevarious modifications in formal features of construction will of coursebe made and they may obviously be made without departure from saidinvention.

In another application Serial blo/107,425, filed by us October 1, 1891,we have illustrated and described a toggle as being positively actuatedin both directions, such construction being therein specifically claimedsubject to the generic claim herein contained. WVe make no specificclaim, therefore, to such mechanism in this application.

XVe claim as our invention:

l. In a clutch or tool holder having relatively stationary andlongitudinally movable parts for the contraction and expansion of theclutch, the combination with the longitudinally movable member, of atoggle for imparting longitudinal motion thereto and means for actuatingsaid toggle.

2. In combination with the relatively stationary and longitudinallymovable members of a clutch device, a toggle arranged to give thelongitudinal movement to one of said members, and a sliding sleeve orring for extending the toggle.

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3. The combination with the tube B provided with e slot, ot e olutoh rodC, a. toggle applied to said rod, and s ring surrounding the tube Barranged to press on the toggle for the extension of tile latter.

4. The combination Twith n tube provided with it slot and interiorlytapered et its end, ot e rod fitted to said tube and carrying springGluten jews Within the tapered end ot' the tube, e toggle arrangedopposite tbe slot and working in tile plone thereof, one of the arms ot'seid toggle being attached to the rod and the other to e stationerypart, L sliding ring einbreeing tbe tube l5 and provided with a presserhaving bearing upon the toggle through the slot.

5. The combination with the slotted tube B, sliding rod G carryingolnteh jews, toggle arms C2 G3, the adj nstsble part C connected withthe toggle, and e sliding ring for extend ing the toggle.

6. The combination of a non-rotating shell composed ot parts of whichthe parts A and A2 ere seperated by e speoe, and at surrounding sleevecovering seid space and adapted to slide on the adje-cent members of theshell, of :t rotating tube B provided with e slot opposite tile space inthe shell and suitably shouldered to tite shell for the retention of theparts et the letter in their pieces on said tube, e rod C Carryingspring j eWs, a toggle attached to seid rod and to n stationery member,a, ring surrounding the tube B and provided with et presser bearing uponthe toggle, and ineens 'for retaining seid ring in pince with respect tothe surrounding sleeve while revoluble with respect thereto,substantially es described.

7. The combination of the shell composed of tbe members A A A2 A3 andsliding member A4 of the revoluble tube B properly shouldered with theseperated portions of the shell for their retention in place thereon,the rod C carrying the spring clutch jews of the clutch proper, tbe adjustable part C", the toggle members C2 C3 connected with the parts C andO4, e spring arranged to flex seid toggle, n. ring a4 revoluble Withinthe sleeve Afl and provided with e presser bearing upon the toggle, andretaining shoulders on the interior ot' the slide A4.

In testimony that We claim the foregoing es our invention We affix oursignatures in presenoe of two Witnesses.

JAMES E. LOV. MAGNUS DAHL.

`Witnessesz C. CLARENCE POOLE, GEORGE W. HIGGINS, Jr.

